The transition metal-catalyzed selective oxidation of unreactive carbon-hydrogen bonds is a direct method or forming alcohols and carbonyl compounds from hydrocarbons under mild conditions. Inspired by remarkable catalytic activity of metalloenzymes in nature, extensive research has been focused on the development of practical catalytic methods for C-H bond oxidation reactions that utilize molecular oxygen as the sole oxidizing agent under environmentally benign conditions. This group has been exploring the activity of highly unsaturated ruthenium complexes with oxygen and nitrogen donor ligands for C-H bond activation reactions. The proposed research presents the detailed plans for studying C-H bond oxidation reactions mediated by novel bimetallic ruthenium-hydroxo complexes.Ihe second part of the proposed research focuses on the catalytic addition reactions of alkenes. In particular, metal-catalyzed conjugate addition of nitrogen and oxygen nucleophiles has been shown to be an effective method for forming a wide variety of biologically important beta-amino acids and -alkoxy ketones. Another reaction of current interest is the asymmetric hydrovinylation of alkenes, which has been shown to be a versatile method for forming new C-C bonds. The proposed research focuses on the development of highly effective chiral ruthenium catalysts for asymmetric conjugate addition of alcohols and hydrovinylation of alkenes. The detailed plans for examining the mechanisms of these reactions are also presented.The proposed research employs well-defined ruthenium-hydroxo and -amido complexes to effect catalytic C-H bond oxidation, conjugate addition of alcohols and hydrovinylation of alkenes. The proposed research seeks for both fundamental mechanistic understandings and the development of effective ruthenium catalysts for asymmetric conjugate addition of alcohols and hydrovinylation of alkenes.